Necrozma moved from BL3 to RU
Ribombee moved from BL3 to RU
Qwilfish moved from PU to NU
Kingdra moved from OU to UU
Mandibuzz moved from UU to RU
Spiritomb moved from NU to PU
Stakataka moved from OU to UU
Lucario moved from BL2 to UU
Heliolisk moved from RU to NU
Venusaur moved from RU to NU
Charizard-Mega-Y moved from OU to UU
Blastoise-Mega moved from UU to RU
Sandslash-Alola moved from NU to PU
Manaphy moved from OU to UU
Marowak-Alola moved from OU to UU
Torkoal moved from RU to NU
Klinklang moved from BL4 to NU
Lycanroc-Dusk moved from OU to UU
Dragonite moved from OU to UU
Silvally-Steel moved from PU to NU
Ninetales-Alola moved from OU to UU
Smeargle moved from RU to NU
Claydol moved from NU to PU
Rotom-Mow moved from NU to RU
Medicham moved from BL4 to NU
Yanmega moved from BL3 to RU
Seismitoad moved from NU to UU
Kommo-o moved from RU to UU
Gengar moved from OU to UU
Rotom-Wash moved from UU to OU
Aurorus moved from NU to PU
Dugtrio moved from RU to NU

Usually the tier changes would go here, but the last time I did this, there were some issues with Mega Pokemon, and I never got around to tracking it down. So: everything above and including (51) Naganadel is Doubles OU. Everything below is Doubles UU.

To be clear, the actual usage numbers were fine, so they contributed 1/8th to this update. I just don't want to post the files until after the rerun so people don't quote / redistribute partially borked data.